RT Journal Article
SR Electronic
T1 Lens power in Iranian schoolchildren: a population-based study
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 779
OP 783
DO 10.1136/bjophthalmol-2017-310565
VO 102
IS 6
A1 Hassan Hashemi
A1 Reza Pakzad
A1 Rafael Iribarren
A1 Mehdi Khabazkhoob
A1 Mohammad Hassan Emamian
A1 Akbar Fotouhi
YR 2018
UL http://bjo.bmj.com/content/102/6/779.abstract
AB Aims To evaluate lens power (LP) in schoolchildren aged 6–12 years.Methods This cross-sectional study was conducted in Shahroud, northeast Iran. The students were selected through random cluster sampling and underwent the measurements of biometry, uncorrected and corrected visual acuity, non-cycloplegic and cycloplegic refraction. The LP was calculated using the Bennett formula.Results Of 6624 invited children, 5620 (84.8%) participated in the study and data of 4870 children were finally analysed. The mean age of the participants was 9.7 years and 2277 participants (46.02%) were girls. The mean LPs were 22.86 dioptres (D) in total study population, 23.91 D in 6 and 22.10 D in 12-year-old children. The mean LP was higher in girls than boys (23.48 D vs 22.34 D), in rural children than urban children (23.17 D vs 22.83 D) and in children with hyperopia (23.25 D) than children with myopia or emmetropia (22.64 D and 22.86 D, respectively). In the multiple linear regression model, lens thickness (β=1.59, p<0.001), anterior chamber depth (β=2.21, p<0.001) and female sex (β=0.016, p=0.015) were associated with an increase in the LP, while axial length (AL) (β=−4.41, p<0.001), corneal power (CP) (β=−1.47, p<0.001), spherical equivalent (SE) (β=−1.50, p<0.001) and age (β=−0.005, p=0.001) were associated with a decrease in the LP. AL and sex had the highest and lowest impact on LP, respectively.Conclusion LP decreased with age between 6 and 12 years and was associated with a shorter AL, deeper ACD, higher SE, thicker lens and lower CP.